Sofa-bed mechanism



0a, 24, 1961 L. POKORNY, JR

SOFA-BED MECHANISM 5 Sheets-Sheet 1 Filed March 8, 1960 JNVENTOR.

LOUIS POKORNY JR {av I ATZZRA/ZFY Och 1961 1.. POKORNY, JR

SOFA-BED MECHANISM 3 Sheets-Sheet 2 Filed March 8, 1960 INVENTOR: LOUIS POKORNY JR BY W W ATTO EV Oct. 24, 1961 L. POKORNY, JR

SOFA-BED MECHANISM 5 Sheets-Sheet 3 Filed March 8, 1960 INVENTOR. LOUIS POKORNY UR.

Arr gawir Filed Mar. 8, 1960, Ser. No. 13,689 1 Claim. (Cl. 5-13) This invention relates to sofa-beds, and more particularly, to a sofa-bed mechanism of simplified construction.

One of the objects of the present invention is to provide certain improvements in sofa-bed mechanisms of the type in which a frame is adjustable between a fully folded sofa position and a fully extended bed position. The continuous-action mechanism shown in my earlier Patent No. 2,832,965 is an example of this kind of frame, and the improvements afforded by this invention will be described and illustrated in connection with a folding sofabed frame of that kind. In the folded position, the entire mechanism is accommodated by an upholstered sofa body, and serves to support the usual removable seat cushions, while in extended position the mechanism stretches outwardly from the sofa body, together with a mattress coextensive and foldable with the mechanism, to define a bed.

A more particular object is to provide a simplified and more efficient linkage system for the adjustment of a center leg from an inactive somewhat horizontal disposition when the frame is in its sofaefining condition and an active upright bed-supporting disposition when the frame is extended.

In the folded condition, the sofa-bed mechanism comprises a rear section, a lower horizontal section, a front vertical section, an upper horizontal section, and a linkage system interconnecting these sections. In the above-mentioned patent, the linkage system includes a lever fulcrumed on the lower horizontal section, a center leg pivoted to the lower horizontal section for supporting the mechanism when in bed-defining, extended condition, and a link pivotally connecting the lever and the leg. With that arrangement, as the lever pivots during the adjustment of the frame, it serves to either fold the leg against the lower horizontal section, or unfold the leg into operative position, depending upon whether the mechanism is being folded or unfolded. In addition, the linkage system includes a connecting link provided between the lever and the rear section, and an elevator arm pivotally anchored on the sofa body and articulated to the connecting link. The length of the elevator arm determines the height to which the mechanism is raised as it moves between folded'and unfolded condition.

The reason that the mechanism must be raised during its conversion from sofa to bed or vice versa, is that the sofa body with which the foldable mechanism is employed is customarily constructed with a fixed front board running horizontally across the lower front region of the sofa. In order to insure that the movement of the mechanism, when it is withdrawn from the sofa, or returned to the sofa, is not interfered with by the front board, the mechanism is actuated so that it moves first upwardly then downwardly in an arcuate path so as to clear the front board of the sofa.

By means of the present invention the linkage system of 3,%5,2ll Patented Oct. 24, 1961 the sofa-bed mechanism is simplified by eliminating the separate bed leg and the link connecting that leg to the lever. Toward this end, one arm of the lever has been extended to form a bed leg, which replaces the former separate leg. This alteration, however, has given rise to a new problem, namely, as the mechanism is unfolded, the bed leg begins to unfold or move away from the lower horizontal section at an earlier point in the movement of the mechanism than the point at which the former separate leg began to unfold. As a result, some means is required to raise the mechanism an additional amount when the bed leg passes over the front board, while at the same time, this means should permit all the elements of the mechanism to assume their proper positions in both the folded and extended condition of the mechanism. Obviously, merely lengthening the elevator arm would not accomplish these ends.

In order to achieve the desired result, the elevator arm, rather than being 'directly connected to the connecting link between the lever and the rear section, as was previously the case, is indirectly pivotally connected to the connecting link by means of a short extension link, disposed between the elevator arm and the connecting link. The extension link is so arranged that when the bed leg passes over the front board, the extension link comes into substantial alignment with the elevator arm, and thus serves to raise the mechanism the additional amount needed to cause the bed leg to clear the front board. In the fully folded or fully extended condition of the mechanism, however, the extension link is disposed at a relatively large angle to the elevator arm, so that it does not interfere with the assumption by the mechanism of its fully foldedand fully unfolded positions. In addition, in order to maintain the stability of the mechanism during its movement, 'a supporting link is provided between the lower horizontal section and the pivot connecting the elevator arm and extension link.

Additional objects and advantages of the invention will a be apparent from the following description.

In the drawings: FIG. 1 is an end view of a sofa-bed mechanism having the improvements of the present invention, the

sofa body, the cushions of the sofa, and the mattress of the bed being shown in dot-dash lines, the mechanism being shown in its fully folded position;

FIGS. 2, 3 and 4 are views similar to FIG. 1, but on a reduced scale, showing the mechanism in successive stages of opening, the bed being almost fully extended in FIG. 4; and

FIG. 5 is a fragmentary perspective view of certain linkage elements at an intermediate stage of opening of the mechanism.

The sofa body within which the mechanism is mounted includes the usual upholstered back 10, sides 11, removable seat cushions l2, legs 13, and a front board 14 which remains fixed in position and extends along the entire length of the sofa. In addition, there is a movable front board 15 mounted on the sofa-bed mechanism and carried along with the mechanism when it is unfolded. The front boards 14 and 15 and the sides 11 may or may not be upholstered depending upon the style of the sofa.

The sofa-bed mechanism comprises four sections pivoted to one another and a linkage system interconnecting the sections. In the fully folded condition of the mechanism, the four sections assume the relative positions shown in FIG. 1. For convenience, these sections will be referred to as the rear section 18, the lower horizontal section 19, the front vertical section 20, and the upper horizontal section 21. The rear section 18 is pivotally connected to the lower horizontal section 19 at 22, the lower horizontal section is pivoted to the front vertical section at 23 and the front vertical section is pivoted to the upper horizontal section at 26. In addition, the rear section 18 is mounted on the sofa body by means of the fixed pivot 27. These pivotal connections and mountings permit the mechanism to be withdrawn from the sofa body into an extended or fully unfolded condition wherein the four sections lie in horizontal alignment to define a bed.

Extending across the sections 18-21 is a bed spring 28 (FIG. .5) which may be anchored to the sections in any suitable manner. The bed spring 2i: serves to support a mattress 29 when the mechanism is in fully extended condition. The mattress 29 is coextensive with the mechanism and folds with the latter into the position shown in FIG. l. In this position, the bed spring 28 and mattress 29 serve to support the seat cushions 12.

The linkage system of the sofa-bed mechanism shown is adapted to produce a continuous action of the mechanism as it moves betwen folded and unfolded condition. This continuous action is fully described in the abovementioned US. Patent No. 2,832,965. The present improvements deal only with certain elements of the linkage system, and hence, only these elements will be described in detail, although the entire linkage system is shown in the drawings.

The elements of the linkage system with which the present invention is primarily concerned are the lever 30*, the connecting link 31, and the elevator arm 34. The lever 30, which is a lever of the first class, i.e., its fulcrum is at an intermediate point on the lever, is fulcrumed at 35 to the lower horizontal section 19. The connecting link 31 has one end pivotally connected at 36 to the rear section 18 and its other end pivoted at 37 to one arm of the lever 30. The elevator arm 34 is pivoted at 38 to a bracket 39 which is fixed to the sofa body, and a tension spring 42 extends between the lower end of the elevator arm and another point on the fixed bracket 39. The bracket 39 as shown in the drawings is on the near side 11 of the sofa housing. According to previous constructions the free end of the elevator arm 34 was pivotally connected to the connecting link 31, and in addition, a separate bed leg member was provided, pivoted to the lower horizontal member 19. Also, a link was provided between the lever 30 and the separate bed leg, to fold the bed leg against the lower horizontal section and unfold the leg into operative position as the mechanism was folded and unfolded.

According to the present invention, the linkage system has been simplified by eliminating the separate bed leg and its associated link, and extending the free arm of the lever 30 in order to form a bed leg 43. The bed leg 43 is so formed that it folds into a position adjacent to and generally parallel to the lower horizontal section 19 when the mechanism is in fully folded condition, and pivots into an operative position perpendicular to the lower horizontal section when the mechanism is in extended condition. As mentioned before, formation of the bed leg 43 integral with the lever 30 gives rise to a new :problem caused by the presence of the fixed front :board 14. It happens that the bed leg 43 begins to unfold away from the lower horizontal section 19 (see FIG. 2) at an earlier point in the unfolding movement of the mechanism than the point at which the previous separate leg began to unfold. As a result, if the elevator arm 43 were, as usual, pivoted directly to the connecting link 31, the lower region of the leg 43 would strike the front board 14 and prevent further unfolding movement oftthe mechamsm.

To a void this undesirable result the elevator arm 34,

rather than being directly pivoted to the connecting link 31, is provided with a short extension link 44, the lower end of which is pivoted at '45 to the free end of the elevator arm. The upper end of the extension link is pivoted at 46 to a point on the connecting link 31. The extension link 44 is so arranged that, during the movement of the sofa-bed mechanism, when the lower end of the bed leg 43 comes toward the front board 14 (FIG. 3), the extension link 44 comes into substantial alignment with the line joining the pivot 38 and the pivot 45, thus momentarily increasing the effective dength of the elevator arm. Consequently, the sofa-bed mechanism is raised a suiticient additional amount to permit the bed leg 43 to clear the front board 14 thus avoiding any undesirable contact between these two members. Furthermore, as will be noticed in FIGS. 1 and 4, the extension'link 44- in no way interferes with the assumption by the sofa-bedmechanism of its normal fully folded and fully unfolded positions.

In order to maintain the elevator arm 34 and extension link 44 in proper relative positions throughout the movement of the sofa-bed mechanism, a supporting link 47 is provided. The supporting link 47 is pivoted at one end to the pivot 45 between the elevator arm and the extension link 44, and its other endis pivoted at 50'to the lower horizontal section 19. It will be noticed that the supporting link 47 is also arranged so as not to interfere with the assumption by the sofa-bed mechanism of its proper positions in its folded and extended conditions.

The operation of the mechanism is as follows: After the sofa cushions 12 have been removed, the upper movable front board 15 is grasped to initiate an upward forward movement of the mechanism as a. whole. Aiding in this movement is the spring 42 which draws rearwardly upon the lower end of the elevator arm 34 and urges the latter to swing upwardly from the position of FIG. 1

toward the position of FIG. 2. During this time the mechanism remains substantially compact, swinging as a unit about the fixed anchorage point 27,. As the board 15 continues forwardly from the sofa housing, the angle between the rear section 18 and the lower horizontal section 19 becomes obtuse (see FIG. 3). As a result the section 19 moves forwardly relative to the connecting link 31, hence the :latter exerts a rearward pull at.37 upon the upper arm of the lever 30. This draws the lower or leg arm 43 of the lever away from its adjacence to the section 19. In the meantime the pivot point 45 is being drawn forwardly by the pull upon it of the supporting link 47, so that when the parts have reached the intermediate stage shown in FIG. 3 the extension link 44 has swung from its acute angle relation to the elevator arm 34 (FIG. 1) to and past a relationship to it .(ata stage between FIGS. 2 and 3.). As the mechanism unfolds further (FIG. 5) the link 44 moves considerably beyond the 180 position and in the condition of the mechanism shown in FIG. 4 it is again at an acute angle to the elevator arm 34 which is now in its furthest forward dispos'ition. The parts resume their folded condition by a reversal of these movements.

Another feature of the invention should here be mentioned. According to previous constructions,-the bed leg which has been replaced with the bed leg 43, contacted the floor before it reached its final operativepositiomiand for this reason it was provided at its lower .end with a roller. The improved bed leg 43, however, doesnot contact the floor until it has reached its final operative position perpendicular to the-lower horizontal section-19. As a result, strain on the elements of the mechanism is reduced, and the need for a roller at the lower end of the bed leg is eliminated, thus lowering the cost of the mechanism.

It will be understood that manyrof the details herein described and illustrated may bemodified by those skilled in the art without necessarily departing from "the spirit and scope of the invention as expressed in .theappended claim. Except as otherwise stated, therefore, it is intended that these details be interpreted as being illustrative only.

What is claimed is:

In a sofa-bed mechanism arranged in a sofa housing having a front board, sections pivoted to one another comprising a rear section and a lower horizontal section, said sections being foldable between a collapsed sofa position and an extended bed position, and a linkage system interconnecting said sections to constrain the mechanism to fold and unfold in accordance with a predetermined pattern of movement, said linkage system including a lever of the first class fulcrumed to the lower horizontal section, a connecting link extending between the rear section and one arm of said lever, the other arm of said lever being extended to define a bed leg, an elevator ann having one end pivoted to the sofa housing, an extension link pivoted to the other end of said elevator arm and extending between said elevator arm and said connecting link, and a supporting link extending between the lower horizontal section and the pivot connecting said elevator arm and extension link, said links being so arranged that the extension link oomes into substantial alignment with said elevator arm to raise the mechanism an added amount as the bed leg passes over the front board during the folding and unfolding movements of the mechanism.

References Cited in the file of this patent UNITED STATES PATENTS Re. 24,128 Creveling et a1. Mar. 13, 1956 2,582,904 Harman Jan. 15, 1952 2,588,071 Arton Mar. 4, 1952 2,656,547 Winikofi Oct. 27, 1953 2,729,829 Bebry Jan. 10, 1956 2,759,198 'Medniek Aug. 21, 1956 2,832,965 Pokorny May 6, 1958 FOREIGN PATENTS 1,092,453 France Nov. 10, 1954 

